Carbon nanotube, as a one-dimensional nano-material, is light and has a perfect hexagonal structure. Carbon nanotubes exhibit many excellent mechanical, electrical and chemical properties, for example, a high current density (over 109 A/cm2), a high thermal conductivity (about 6,600 W/m·K), and a high light transparency (over 90%). Owing to these remarkable properties, carbon nanotubes, in particular single-walled nanotubes, have been used in thin film transistors.
At present, carbon nanotube thin film transistors are generally made of heavily doped silicon wafers. As illustrated in FIG. 1, a silicon wafer is configured to function as both a base substrate and a gate electrode in the carbon nanotube thin film transistor, a layer of silicon dioxide disposed on the silicon wafer is configured to be a gate insulation layer, further a layer of carbon nanotubes disposed on the gate insulation layer is configured to be a semiconductor layer, and finally a source electrode and a drain electrode are manufactured on the active layer made of carbon nanotubes.
At present, the carbon thin film transistor is still in a stage of research and development, in order to ensure the performance of a device which comprises the carbon thin film transistor, a rigid substrate is employed, but the rigid substrate hinders its application in a flexible device. Furthermore, in the single-walled carbon nanotubes manufactured in the current methods, about two thirds of the carbon nanotubes are semiconducting and about one third of the carbon nanotubes are metallic, the coexistence of the semiconducting and the metallic carbon nanotubes greatly limits the electrical property of thin film transistors.